Python script renders a collection even when excluded from view layer
I did this recently, you have to access your collection through specific view layer.
You should try :
my_view_layer = bpy.context.view_layer #up to you

#append to sideplates only checked collection
sideplates = []
for collection in my_view_layer.layer_collection.children[&quot;RACK 1 - 1 RACK FRAME&quot;].children :
    if collection.exclude == False :
        sideplates.append(collection)

##render individually checked collections
for s in sideplates:
    
    #exclude every other collection
    for sp in sideplates:
        if sp != s :
            sp.exclude = True
            
    ## RENDER STUFF ##
    
    #restore exclude attribute
    for sp in sideplates:
            sp.exclude = False